The caffeine in Celsius comes from three sources: guarana seed extract, green tea leaf extract, and caffeine anhydrous (a purified, dehydrated form of caffeine). All three are part of the drink’s proprietary MetaPlus Thermogenic Blend, and together they deliver 200 mg of caffeine in a standard can or 300 mg in the Celsius Heat line.
The Three Caffeine Sources
Celsius doesn’t rely on a single caffeine source. Its MetaPlus blend combines plant-derived caffeine with a refined form, each playing a slightly different role in the formula.
Guarana seed extract is a plant native to the Amazon basin whose seeds naturally contain caffeine, typically at higher concentrations than coffee beans. Celsius lists this as a key caffeine source and describes it as “a safe, plant-derived form of caffeine.” Guarana has a long history of use in energy drinks and supplements throughout South America.
Green tea leaf extract is standardized to 10% EGCG, a compound in green tea that supports thermogenesis (your body’s ability to burn calories as heat). Green tea leaves naturally contain caffeine, so this extract contributes some caffeine to the total count while also serving a separate purpose in the formula. Research has found that caffeine and green tea extract together are the principal active ingredients driving the thermogenic effect Celsius markets itself around.
Caffeine anhydrous is simply caffeine in its pure, dehydrated powder form. It’s the same molecule your body gets from coffee or tea, just isolated and concentrated. This is the most common form of caffeine used across the supplement and energy drink industry, and it allows manufacturers to hit precise milligram targets on the label.
How Much Caffeine Each Line Contains
The total caffeine from all three sources varies by product:
- Celsius Original: 200 mg per can
- Celsius Essentials: 200 mg per can
- Celsius Heat: 300 mg per can
For context, a standard 8-ounce cup of brewed coffee contains roughly 80 to 100 mg of caffeine. So a can of Celsius Original is comparable to about two cups of coffee, while Celsius Heat lands closer to three.
Does Plant-Derived Caffeine Work Differently?
You might assume that caffeine from guarana or green tea hits your body differently than the purified stuff. It doesn’t. A study comparing caffeine release and absorption from guarana against an equivalent dose of free caffeine found no significant differences at any pH level tested. The caffeine molecule is identical regardless of its source, and your gut absorbs it at the same rate whether it came from a guarana seed or a lab.
Some people report that guarana-containing drinks feel “smoother” or longer-lasting than pure caffeine. This perception likely comes from other compounds in the plant matrix, like tannins, which can slow how quickly the full dose reaches your bloodstream in a whole-food context. But once caffeine is extracted and dissolved in a carbonated drink, that buffering effect largely disappears.
Why Celsius Uses Multiple Sources
Blending caffeine sources is partly functional and partly about marketing. The guarana and green tea extracts aren’t just caffeine delivery vehicles. They bring along other bioactive compounds. Green tea’s EGCG, for instance, has been shown to boost 24-hour energy expenditure by about 4.6% when consumed alongside caffeine and calcium in controlled studies, though the doses used in that research (around 700 mg of catechins per day) are higher than what a single can of Celsius provides.
The combination also lets Celsius position itself as a “fitness drink” with plant-based ingredients rather than just another caffeinated soda. Listing guarana and green tea on the label signals a different category to consumers, even though the caffeine itself works identically once it’s in your system.
The NCAA Guarana Question
One concern that surfaces around Celsius, especially among college athletes, is whether guarana-derived caffeine creates problems under NCAA substance rules. The NCAA lists caffeine as a controlled substance at high concentrations (above 15 micrograms per milliliter in urine), and guarana appeared on their documentation as an example of a caffeine source. This led some athletes to worry that guarana was separately banned. In June 2025, the NCAA clarified that guarana is simply one example of where caffeine comes from, not a distinctly prohibited ingredient. The organization that handles NCAA label reviews confirmed that guarana “is not specially banned” but is just a natural source of the same regulated stimulant.